Manchester United defender Chris Smalling has admitted his team mates 'let themselves down' in the 3-1 win over Burnley.

Despite being thoroughly outplayed by Sean Dyche's fearless side at Old Trafford, UNited still somehow finished the first-half 2-1 ahead courtesy of two Smalling goals.

Smalling, who replaced the injured Phil Jones on five minutes and 22 seconds later nodded in the opener, acknowledged winning without playing well was a useful habit, but could not hide his disappointment at a dreadful first 45 minutes.

“It wasn’t a 3-1 scoreline game,” Smalling told MUTV. “Especially in that first half, we all let ourselves down. We could have played much better.

“They came out of the traps, they pressed us well, but we didn’t find the solutions to that in the first half. We were very lucky to come in at half-time ahead. We knew that Burnley run hard and they run the channels. We knew their game-plan but we didn’t get to grips with it.”

“It helped settle us a little bit going into the second half. That second-half was a little bit more like Manchester United. But that first half… we need to look at ourselves and make sure it never happens again.“

Smalling became the first ever substitute to score a first-half brace in the Premier League

Despite moving up to third in the Premier League table, some United supporters whistled the side at Old Trafford, which Louis van Gaal admitted was a 'concern', and Smalling is well aware of the standards set at Old Trafford.

“There is [more to come],“ he added.

“But the manager said in the dressing room that the first half was unacceptable and all the players know that. If we can win games playing that badly, then it shows that if we do play well and it all clicks, then there will be a lot better performances at Old Trafford, that’s for sure.”

“In the second half, we played a lot better and we just needed to get that third goal. We kept pressing them and we were a lot more patient on the ball than we were in the first half.”